We study the evolutionary biology of birds and relatives, combining field, museum and genomics approaches to understand the basis of avian diversity, evolution and behavior. Our guiding approaches include population genetics, which provides a quantitative framework for studying speciation, geographic variation and genome evolution; systematics, which acknowledges that the focal species of any study has relatives that are behaviorally and ecologically no less interesting; and natural history, which gives meaning to the genes and genomic patterns we study.